91. Which one of the following chemicals helps in fruit ripening?

1. Ethephon
2. Atrazine
3. Isoproturan
4. Malathion

Option “A” is correct
The Chemical Ethephon is often used on wheat, coffee, tobacco, cotton and rice in order to help the plant’s fruit to ripen more quickly.
92. Which of the following is not a Natural polymer?

1. Wool
2. Silk
3. Leather
4. Nylon

Option “D” is correct
Wool, silk, leather are the natural polymers but nylon is not a natural polymer.
93. Which one of the following chemicals had been in use till now for making artificial clouds?

1. Potassium Nitrate
2. Heavy Water
3. Sulphur Iodide
4. Silver Iodide

Option “D” is correct
Cloud seeding is the process of spreading either dry ice or more commonly silver Iodide into the upper part of clouds to try to stimulate the precipitation process and form rain.
94. ___________ Gases absorb long wave (infrared) radiation from the earth and emit it again towards the earth.

1. Hydrogen
2. Nitrogen
3. Carbon dioxide
4. Ozone

Option “C” is correct
A greenhouse gases are combination of gases in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect.The main Greenhouse Gases are Carbon di oxide, Methane, Ozone, Water vapour etc.
95. Metals react with sodium hydroxide to produce ___________.

1. Oxygen gas
2. Sodium
3. Water
4. Hydrogen gas

Option “D” is correct
Sodium hydroxide reacts with metal to release hydrogen gas. The metal takes the oxygen atom from sodium hydroxide, which in turn takes the oxygen atom from the water, and releases the two hydrogen atoms. The reaction thus produces hydrogen gas.
96. Which base is present in lime water?

1. Sodium hydroxide
2. Magnesium hydroxide
3. Calcium hydroxide
4. Ammonium hydroxide

Option “C” is correct
Calcium hydroxide base is present in lime water.
97. Chemical formula for Sulphurous acid is:

1.H2SO4
2.H2SO3
3.H3SO3
4.H3SO4

Option “B” is correct
Sulfurous acid is the chemical compound with the formula H₂SO₃.
98. Brownish film formed on iron when left in open is called?

1. Dust
2. Shovel
3. Spade
4. Rust

Option “D” is correct
When iron is exposed to water or air over a period of time, the iron reacts with oxygen in the presence of moisture to form a reddish-brown chemical compound, iron oxide. This is referred to as rust.
99. The substances which have very low ignition temperature and can easily catch fire with a flame are called _____________ substances.

1. Hazardous
2. Perilous
3. Incombustible
4. Inflammable

Option “D” is correct
The substances which have very low ignition temperature and can easily catch fire with a flame are called inflammable substances. Examples of inflammable substances are petrol, alcohol, Liquified Petroleum Gas (LPG), etc.
100. Which of the following main elements is used in making matchbox?

1. Graphite
2. Phosphorous
3. Silicon
4. Sodium

Option “B” is correct
The safety matchbox ignites due to the extreme reactivity of phosphorus with the potassium chlorate on the match head. Phosphorus is a highly reactive, non-toxic-chemical used for making the head of a matchstick.

10 thoughts on “Chemistry”

  1. I Love chemical…it’s my favourite subject..mere iss mein se hmesha hi boht ache marks aate hai….and my interest is also in chemistry…

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top